Aircraft release mechanism



B. 5. MILL AIRCRAFT RELEASE MECHANISM I July 12, 1949.

2 Sheets-Shet 1 Filed Aug. 7, 1946 IN V EN TOR.

H ATENT ATTORNE" 2 Sheets-Sheet 2 Filed Aug, 7, 1946 Billy 8. MillINVENTOR PATENT ATTORNEY Patented July 12, 1949 UNITED PATENT OFFICEAIRCRAFT RELEASE MECHANISM Billy S. Mill, Seattle, Wash, assignor toBoeing Airplane Company, a corporation of Delaware Application ugust 7,mac, Serial 533 954 (c1. are-1) 12 Claims.

'l-he present invention relates to improvements n l e iee n 's' 'ne a im re P t u y to releasing and latching arrangements for emerencyequipment aircraft other vehicles It hasheen "the general practice forsome time t0provide landtyp aircraft which are flown over water withemergency gear for'the support of either the'ai're reagar its occupants;orhoth. Small airplanes a e frequentlfbeen provided with"'efnergricyflotation "gear'which is usually stowed withii'the fuselage or otherportions of the airplane 'silch einiergency flotation "gear may heactuated'eithermanually by an occupant or automati ally" upon contactwith the water to open its covering 'or'doors and to cause the gear't'obecomeinflated to provide buoyancy for the desired'portlon or theairplane and to assist inits'fiotationu ojn the surface drtn'e' w terfor a predetermined priodllri larger-aircraft the practicehasffi'equen'tl been to provideone or more inflatable rife-ran which arestowed within convenient compartments in the airplane for manual orautomatic actuation in the event of an emergency landing o'r' ditchingoperation upon the water to serve as life-saving floats for theoccupants ofthe aircraft Such'emefgency flotation gear or life rafts areusually infiated'w'ith air or carbondioikidestored within pressurecylindersorbottle's. Inasmuch as the deflated gearin its'stovvedcc'indition must be protected and coveredwhennot' in use'f'therelease mechanism usually includes a suitable latch' :01? the.co'verspf' thecori ipartment and means I tor "simultaneously or'seqoennanyanp': ping or releasing both the latches for the compartmentcovers and the valves of "the-storage bottles for inflation of theemergency gear. can s-iderabl difiicutty has been met with in priordevices or"-1atch-i-ng'and releasing the compartmerit closures and] thebottle valves; and "instances have occurred Where such"emergency gearhas-become ejected and inflated unintentionally during flightltothe-embarrassment and inconvenience of the'pilot and occupants.Heretofore much difilc'ulty has been met with 'in checking, testing andresetting the latching and release devices for such emergency gear. Thepresent invention is directed to improvements in such latching, andresetting release devices, and the arrangement of their installation,and eliminates to a "great extent most of the difficulties anddeficiencies met with in prior devices intended for these and similarpurposes. The present invention :more tpanticularly'resides in animprovement upon the subjectwmatter covered 2. by Patent r7339??? whichissued October 2, 1 -N- .Mq e th a for a Airplane mfi enc'y fl itatioise It :i'seccordingfi a principal object of the presnt ri eiif pntp' nfie an im e k: t n at henq elea e mechan sm o e e fer inflatabl eqipment e a r a and other vehicles. It is a further' object to provide aer v' 's m l enism fe h l qs v sequential e ees Fi a i JFgPil Y al-c m m(i and the'ai itomatic'iniiation of the gear immediatew 'upon release ofthe door latches. It is a further object to provide 3, quick-acting release device of the pin type adapted to prevent am ingb: the latches andin which the relea's'e'act'ion is assisted'lqy the energy stored in e m9"l? ii m nt A fu t Qbi t lies in prpvi me such a release mechanism whichis easily testedan cl'readily resettable.

a'still furtherobject' of the present inventibnto provide a simplefool-proof latching mechanisr'n'for'the actuation of an inflatableemergency gear which mechanism embodies a lock tangent unintended'unlatching and is of was i 'i k to fio'me ene in flight due tovibration a d "other causes. Further'objects of thifs invention includethe arrarigernent "of inflatable emergency gear within compartmentscovered "by doors which are released immediatelyprior' to inflationofthe gear and ln which? the release action may be manually orautomaticallyinitiated non one or more points'remote'i'rom theinstallation of the gear. Other objects and advantages of the presentinvention'will become apparent to those skilled in the an af-terreading'the present specification taken together -v vitl'i'the "accompanyingdrawings formingaparthereohin whichz' Fig'll is a perspective View ofthe latching and release mechanis'ni'f 'or a dual installation ofinfiatable li fe r'aftsf Fig. 2is aperspective view of the dualcompartment installed in the upper portion of an airplane fuselage withthe nearer one of the c0mpertinent doors opened} Fig. 3 'is a similarperspective View of a pin type latching mechanism as provided along therelease "hinge of the compartment doors; and

Figs. 4a," 4b and 40 show progressive stages in theresetting of thelatching mechanism.

ReferringnowtoFigs; l and 2, the numeral I-B' indicates the fuselage ofan airplane in the upper portion ofwhicli are provided a pair oflaterally disposed life raft compartments provided with the'closui'es ordoors ill and I2. The

nearer door Ii is shown in its fully opened position revealing withinthe raft compartment the folded and stowed life raft I3 indicated inbroken lines and which has connected to it the inflat- Zing bottle M.The compartments are defined by the transverse fuselage bulkheads Idaand Itb and the intermediate longitudinal bulkheads Its. A suitablelanyard or painter It may be supported in a coiled position upon thebulkhead Iila, being attached to the raft I3 in such a manner that thelatter will not be 'caused to float too far from the aircraft while itis upon the water. The lanyard I5 also provides suitable means by whichthe occupants may pull the raft closer to the floating or partlysubmerged airplane for more convenient access to it.

The door II is preferably hinged at its lower outer edge by means of thehinge units It. The latch mechanism preferably consists of a plural-.

ity of units I! mounted upon the longitudinal beam structure I8immediately above the central bulkhead I 00. Each of these latch units,as shown in the perspective view in Fig. 3, consists of a bracket IIahaving spaced projecting lugs I'I'b each of which is slotted at I'Ic toreceive at its upper end a latch pin I9. The latter pin is carried at apredetermined spacing above an elongated guide rod 20 from which it isintermediate ly spaced by the spacers I911, the guide rod 29 extendingthrough the lower end of each of the lug slots in each of the severalunits I'I. Immediately adjacent and forming a part of each of the latchunits I I is a downwardly facing bracket I M which serves as a guide forthe guide rod 29 and maintains the latter in its proper position at thebottom of the grooves or slots "0. The brackets Ila and Ill) aresuitably attached to the web of the beam structure l8 by the bolts Heand the upper flange of the beam has attached thereto a hollow spacingelement I8a which serves to maintain a flush and continuous outersurface between the contiguous edges of the closures I I and I2.

Each closure carries at its releasable edge the lugs 2I which arelocated in the spaced positions corresponding to the gaps between theslotted brackets I'Ib, each being of a length suitable for receptionbetween the slot-ted lugs of the corresponding unit I'I. These lugs 2|are suitably apertured to receive the latching pins I9 which havepointed ends I9b, and it will accordingly be noted that when the guidebar 20 is pulled toward the right in Figs. 2 and 3 into the positionshown in Fig. 3, the pins I9 are withdrawn from the apertures in thelugs 2| as well as from the slots in the brackets I'Ib to permit thedoors to be rotated outwardly about the hinges I 6 into the openposition shown in Fig. 2. Referring to Fig. 1, there is shown mountedupon the rear transverse bulkhead Iilb and the reenforcing plate Illd, arelease assembly 22 attached to the bulkhead and reenforcing plate bymeans of the mounting bolts 22a. This release assembly 22 also embodiesa lock which prevents unintentional unlatching of the life raft doors IIand I2, or undesired release of the carbon dioxide bottle M. The releaseand lock assembly is of the dual type serving to latch or unlatch theadjacent edges of both doors as well as to release the inflating bottlesof each of the adjacent life rafts. The doors and bottles are normallyactuated individually as a unit on I either side of the fuselage butboth units can be operated simultaneously if desired by pulling on 4these remote release handles 23a, 24a, 25a and 26a respectively. Thecables preferably extend through flexible tubing 21 which may be oftinned wire type suitably guided and supported as at 28 from thefuselage structure Ille. The transverse bulkhead Ifib is suitablyapertured to permit the pins i9 and guide rods 20 to extend therethroughas well as the pair of flexible tubes 29 within which the cables 30extend forwardly to the inflating bottles I4.

In Figs. 4a, 4b and 40, a locking and release assembly 22 is shown inthe released, partially reset and latched positions respectively.Resetting handles M are fixedl attached to the ends of each of the latchpin guide rod 29 and a latch coil spring 32 co-axially encircles each ofthese ends of the guide rods. Inasmuch as the latch pins I9 frequentlytend to stick or bind in the lugs Ill) and iii, the incorporation of thecompression spring 32 in the releasing mechanism assists by imparting asharp pull upon the guide rod 20 to provide a quick-action device whichsnaps the pins into their released or unlatched positions. A releaseslide member 33 has an upper apertured bore portion 33b which alsoencircles the rear portion of the guide rod 20 and cooperates with thehandle 3| to compress the spring 32 when the release slide member 33 ispulled rearwardly by the above mentioned release cable 23 to which it isattached by the clevis or other terminal connection 23b. The releaseslide member 33 has a downwardly extending portionto which is attachedthe rearward terminal of the pressure bottle release cable 30 throughthe medium of the attachment loop 30a. As stated above, when the cable23 is pulled to the right in Figs. 4a, 4b and 4c, the spring 32 will befurther compressed as the release slide member 33 pulls toward theright, provided of course that the re-' setting handle 3| does not move.For this reason a lock device is provided to restrain movement of thehandle 3| until such time as the spring 32 has been compressedsufficiently to pull the latching pin 20 with a snap action when thehandle 3| is permitted to move.

The release assembly 22 is supported from the transverse bulkhead I9?)and the intermediate spacing plate Ifld by the aforementioned mountingbolts 22a passing through its back plate portion 22b from the sides Ofwhich a plurality of brackets 220 are integrally formed. Between eachpair of these brackets there is pivotally mounted a locking wheel 35having a notch 36 in its periphery, the wheel being rotatably mountedupon a pivot or axle 31 journalled within the brackets 22c. Attached tothe resetting handle 3| is a forwardly extending hooked bar 34 (whichmay be slidably guided by the release slide member 33) and has itsdownwardly extending hooked portion adapted to engage the notch 36 inthe locking wheel 35. The forward face of the release slide 33 isprovided with a triangular notch 33a adapted to be engaged by thesimilarly triangular shaped toe 38 of the locking wheel 35. The snapaction of the release mechanism may be augmented by the inclusion of anauxiliary spring 39 attached to one of the lobes of the locking wheel35, the auxiliar spring bearing against the stop pin 4!] which ispreferably disposed between the adjacent spaced shoulders or lobes onthe cam or looking wheel 35 to prevent over travel of the locking wheelin either direction.

Referring now to Fig. 40, which shows the release assembly in its resetand latched condition, let us assume that only the left or port liferaft is to be released and inflated. It will be understood that theaction can be initiated either interiorly of the fuselage by pulling onthe handle 24a, or exteriorly of the fuselage by opening the access door4| and pulling on the handle 23a. Both release cables 23 and 24 areattached to the same release slide member 33 and pull on either cable tothe rear, or to the right in Fig. lc, will tend to move the releaseslide 33 into the unlocked position shown in Fig. 4b. In the latterfigure, it will be noted that the release slide 33 has moved toward theright a sufficient distance that the toe 38 of the locking wheel 35 hasbeen moved out of the notch 33a in the release slide due partly to thetendency of the hooked bar 36, to move to the right, and the tendency ofthe spring 39 to impart clockwise movement to the locking wheel 35. Asthe release slide is pulled toward the right, therefor, the handle 3! isheld against movement in the same direction by the hooked bar 34 the endof which is received in the notch 35 in the periphery of the lockingwheel 35. As long as this wheel 35 is prevented from rotating from theposition shown in Fig. lb about its axle 31, the handle 3| cannot moveto the right as shown in this figure for releasing the latch pin 20.

Rotation of the locking wheel 35 is prevented by engagement of its toeportion 38 in the notch 33a formed in the release slide 33. The lengthof the toe 38 governs the degree of movement of the slide 33 toward thehandle 3| which must be effected before the handle 3| can move to pullthe pin 23. As soon as the slide 33 has been moved far enough to clearthe toe 38 of the wheel 35, it is rotated clockwise into the positionshown in Fig. 4a to release the end of the hooked bar 34, this clockwiserotation being assisted by the energy stored in the auxiliary spring 39.By the impetus which this latter spring gives the wheel 35, it assiststhe coil spring 32 in forcing the handle 3| to the right, and the guiderod 23 in the same direction, when the notch of the release slide 33clears the toe 38. The carbon dioxide bottle release cable 33 isattached to the downwardly projecting portion of the release guide 33 inorder that a continued pull to the right on the guide by the cable 23will subsequently release the carbon dioxide bottle to eject and inflatethe life raft. The releasing movement of the guide rod 23 to the rightis arrested, after the pins 59 are withdrawn from the latching lugs 2|,and the valve of the bottle I4 is fully opened by a suitable stop on thevalve actuator, or a limit stop ma preferably be provided on the guiderod and pin assembly |920 to abut against the face of the bulkhead walllb.

The sequence of movement of the parts of the release assembly 22 toreset the lock is illustrated in the three portions of Fig. 4. Pressureon the resetting handle 3| tending to move it toward the left in thesefigures, is transmitted through the spring 32 which urges release slide33 to the left with the handle 3| until it engages the back of the toe38 on the cam wheel 35. The end of the hooked bar 34 fitting into thenotch 35 of the cam wheel will cause the latter to rotate in acounterclockwise direction against the action of the auxiliary spring39. Since further movement of the release slide 33 to the left will beprevented by its engagement with the cam wheel, continued pressure onthe handle 3| will compress the spring 32 as the cam wheel 35 is rotatedin a counterclockwise direction. As a matter of fact, the slide 33 willactually be forced to the right somewhat as the toe 38 of the cam wheel35 moves upward against it. When the wheel 35 has been rotatedsufiiciently to bring the toe 38 into registry with the notch 33a .intheslide 33 the pressure of the spring 32 will force the slide 33 to theleft over the toe 38 on the cam wheel to bring the parts into theirlocked position. In an actual installation a cable pull throughapproximately 1 inches gave very satisfactory results. The stop pin 40with which the spaced shoulders on the wheel 35 ma abut, preventsover-travel of the wheel in either direction and limits thecounterclockwise rotation of the wheel to establish the reset or cockedposition of the elements of the assembly as shown in Fig. 4c and fromwhich position the closure doors and inflating bottles can again beactuated by tripping the release assembly.

The described mechanism provides an efficient and easily operatedreleasing gear which is both positive and quick acting to sequentiallyunlatch compartment door and to automatically inflate the life raftcontained within the compartment. It will be noted that this mechanismcontains a fool-proof featureto prevent unintended unlatching due tovibration and other causes and its unlatching operation 'is accompaniedby a action release which prevents jamming of the latching pins. Thepresent release gear and latching mechanism has been found particularlysatisfactory in life raft release installations which require frequentchecking and testing, and has proven very desirable in theseinstallations due to the facility with which the gear can be quicklyandpositively reset. It will be understood that the life raft is stowedwithin the compartment in a deflated. condition preferably rolled into acarrotor cone-shape with'its large end toward the front. The deflatedand partially rolled raft pushed laterall into the compartment with itsunrolled portion toward the middle in order that the raft willautomatically eject itself when the valve of the carbon dioxide bottleis opened. It will also be understood that as the raft is inflated and.is automatically thrown overboard to the side of the fuselage thelanyard or painter l5, which is attached at one end to the raft, will beuncoiled to tether the raft to the aircraft in order that it will notfloat out of reach of the occupants.

Other forms and modifications of the present invention both with respectto its general arrangement and the details of its respective parts areintended to fall within the scope and spirit of this invention as moreparticularly set forth in the appended claims.

I claim:

1. In a vehicle body provided with a compartment for a releasablemember, a closure for said compartment releasably attached to said body,a latching assembly supported upon said body operatively connected tosaid releasable closure attachment, releasing means operatively engagingsaid latching assembly and resilient means associated with said latchingassembly arranged to resiliently bear against said releasing means tomaintain the same in a locked condition of the latching assembly and toimpart snap action to said releasable closure attachment upon thelatching assembly being tripped by said resiliently opposed releasingmeans.

2. In aircraft, a compartment, a closure for said compartment releasablyattached to the aircraft, an inflatable member normally stowed withinsaid compartment, arelease assembly for said inflatable member and saidcompartment closure 7. including'a latching mechanism supported upon theaircraft operatively connected to the closure attachment-and. resilientmeans operatively associated with said latching mechanism arranged tomaintain said mechanism in its locked condition and to be furthercompressed as said assembly is released to impart .a quick-acting forcefor the unlatchi-ng of said closure assembly prior to the actuation-ofsaid inflatable member.

3. In a vehicleibody provided with a compartment, an inflatableflotation element in said compartment, a closure for said compartmentreleasably attached to said body, inflating means operatively connectedto said flotation element, a latching assembly supported upon said bodyoperatively connected to said releasable closure attachment and to saidinflating means, releasing means operatively engaging said latchingassembly resilient means associated with said latching assembly arrangedto resiliently bias said releasing means to maintain the same in alocked condition and to impart snap action to both said releasableclosure attachment and said inflating means upon being tripped by saidreleasing means.

41*In a vehicle body provided with a compartment'for a releasablemember, a closure for said compartment releasably attached to said body,a latching assembly supported upon said body operatively connected tosaid releasable closure attachment, resilient means associated with saidlatching assembly adapted to maintain the same in-a locked condition,and actuating means associated with said latching assembly adapted toimpart energy'to said resilient means upon actuationof said latchingassembly which energy imparts snap action to said releasable closureattachment.

5. In a vehicle body provided with a compartment, an inflatableflotation element in said compartment, a closure for said compartmentreleasably attached to said body, inflating means operatively connectedto said flotation element, a latching assembly supported upon said bodyoperatively connected to said releasable closure attachment and to saidinflating means, said assembly including a rotatable element and aslidable guide element engageable by said rotatable element, resilientmeans associated with said latching'assembly adapted to maintain saidrotatable and guide elements in a locked condition, actuatingmeansconnected to said guide element for applying tripping movement theretoagainstthe opposition of said resilient means in such manner as toaid inimparting snap action to said closure release upon tripping of saidlatching assembly.

6. Ina vehicle body provided with a compartment,'an inflatable flotationelement in said comap'artment, a closure for said compartment releasablyattached to said body, inflating means operatively connected to saidflotation element, a latching assembly supported upon said bodyoperatively connected-to said releasable closure attachment and to-saidinflating means, said assembly including a rotatable element and aslidable guide element engageable by said rotatable element, resilientmeans associated with said latching assembly adapted to maintain saidrotatable and guide elements in a locked condition, said resilient meansaiding in imparting snap action to said releasable closure attachmentupon being tripped and means attached to said releasable closureattachment and to said latching assembly through the intermediacy ofsaid resilient means for resetting said latching assembly subsequent toits being tripped.

7. In a device for the'release of a closure from a supporting body, pinmeans extendable through aligned apertures in said closure and saidbody, a tongued element rotatably mounted upon said body, an abutmentcarried by said pin means, an actuating element slidably mounted uponsaid pin means and having a recess engageable by the said tonguedelement, resilient means interposed between said actuating element andsaid pin abutment to maintain said device in the extended latchedcondition of said pin means, locking means carried by said pin meansengageable with said rotatable element in such manner that move ment ofsaid actuating element away from Said rotatable element permits releaseof said tongue and said pin locking means, and said resilient meansimparts snap action retraction to said pin means against its saidabutment for the rapid unlatching of said pin means from said alignedapertures.

8. In a device for the release of a closure from a supporting body, pinmeans extendable through aligned apertures in said closure and saidbody, a tongued element rotatably mounted upon said body, an actuatingelement slidably mounted for longitudinal movement with respect to saidpin means, said actuating element having a recess engageable by the saidtongued element, coil spring means disposed about said pin means betweena fixed portion thereof and said actuating element to maintain saiddevice in the extended condition of said pin means and the latchedcondition of said closure, locking means carried by said pin meansengageable with said rotatable element in such manner that movement ofsaid actuating element away from'said rotatable element permits rapidrelease of said tongue and said pin locking means assisted by said coilspring means, and movement of said pin means in the opposite directioncauses said locking means to engage said rotatable elementand the tongueof said rotatable element to engage said actuating element for theresetting of said release device.

9. The arrangement in a vehicular body comp'artment as set forth inclaim 1 characterized by the inclusion of resetting means operativelyassociated with said latching assembly and resiliently opposing throughsaid resilient means the releasing movement of said releasing means.

10. The arrangement in a vehicular compartment as set forth in claim 4characterized by the inclusion of manual resetting means operativelyassociated with said latching assembly and resiliently opposingreleasing movement of said releasing means through the medium of saidresilient means.

11. A release mechanism for latching a relatively movable member to arelatively fixed member comprising a latch element engageable with saidfixed and movable members, pivotally mounted detent means, a hookelement carried by said latch element engageable with said detent meansin the latched position of said mechanism,

a slidably mounted release element having a portion engageable with saiddetent means in the latched position of said mechanism and in theengaged condition of said hook portion, and resilient means urging saidrelease element into its engaged position in which it prevents rotationof said detent means and retention of the said hook element and saidlatchelement.

12. A readily resettable release mechanism for latching a relativelymovable member to a relatively fixed member comprising a latch elementengageable with said fixed and movable members, pivotally mounted detentmeans, a hook element carried b said latch element engageable with saiddetent means in the latched position of said mechanism, a slidablymounted release element having a portion engageable with said detentmeans in the latched position of said mechanism and in the engagedcondition of said hook element and resilient means urging said releaseelement into its engaged position in which it prevents rotation of saiddetent means and the retention of the said hook element and said latchelement, releasing movement of said release element initially serving tocompress said resilient means prior to release of said hook elementwhereafter the energy of said compressed resilient means is imparted tosaid latch elements for the quick opening of said latch mechanism, andresetting 10 means associated with said latch element whereby movementin a direction opposite to said releasing movement causes said hook andrelease elements to engage said detent means and is aided by saidcompressed resilient means for maintaining said release element in thelatched condition of said mechanism.

BILLY S. MILL.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,774,625 Alexander Sept. 2, 19302,264,321 Manson Dec. 2, 1941 2,353,440 Bresee July 11, 1944

